Delta IV Heavy

The Delta IV Heavy (Delta 9250H) is an expendable rocket, the largest type of the Delta IV family. It was first launched in 2004.

It is similar to the Medium+ (5,2), except that it uses two additional CBCs instead of using GEMs. These are strap-on boosters which are separated earlier in the flight than the center CBC. The Delta IV Heavy also features a stretched 5-meter composite payload fairing. An aluminum trisector (3 part) fairing derived from the Titan IV fairing is also available. The first launch in 2004 was a test launch only. Its first payload was the DSP-23 satellite.

Capacity (separated spacecraft mass) of the Delta IV Heavy:

• Low Earth orbit (LEO) 22,950 kg
• geosynchronous transfer orbit (GTO) 13,130 kg (28,950 lb).
• geosynchronous orbit (GEO) 6,275 kg
• escape orbit 9,306 kg
• C₃ performance of 30 km2s−2: 5,228 kg
• C₃ performance of 60 km2s−2: 2,521 kg

The Heavy's total mass at launch is approximately 733,000 kg, much less than that of the Space Shuttle (2,040,000 kg), but is not reused.

The Orion Multi-Purpose Crew Vehicle is planned for an unmanned test flight launch, known as EFT-1, aboard a Delta IV Heavy rocket in 2014. If launched, it would be its first launch into orbit.